diff --git a/src/Spring/Spring.Core/Util/NumberUtils.cs b/src/Spring/Spring.Core/Util/NumberUtils.cs
index 50508b05..f4338b8a 100644
--- a/src/Spring/Spring.Core/Util/NumberUtils.cs
+++ b/src/Spring/Spring.Core/Util/NumberUtils.cs
@@ -141,15 +141,15 @@ namespace Spring.Util
             else if (number is Int64)
                 return ((Int64)number) == 0;
             else if (number is UInt16)
-                return ((Int32)number) == 0;
+                return ((UInt16)number) == 0;
             else if (number is UInt32)
-                return ((Int64)number) == 0;
+                return ((UInt32)number) == 0;
             else if (number is UInt64)
                 return (Convert.ToDecimal(number) == 0);
             else if (number is Byte)
-                return ((Int16)number) == 0;
+                return ((Byte)number) == 0;
             else if (number is SByte)
-                return ((Int16)number) == 0;
+                return ((SByte)number) == 0;
             else if (number is Single)
                 return ((Single)number) == 0f;
             else if (number is Double)
diff --git a/test/Spring/Spring.Core.Tests/Util/NumberUtilsTests.cs b/test/Spring/Spring.Core.Tests/Util/NumberUtilsTests.cs
index 81d3d8ac..553a8220 100644
--- a/test/Spring/Spring.Core.Tests/Util/NumberUtilsTests.cs
+++ b/test/Spring/Spring.Core.Tests/Util/NumberUtilsTests.cs
@@ -65,20 +65,51 @@ namespace Spring.Util
 		}
 
 		[Test]
-		public void IsNumber()
+       public void IsNumber()
 		{
-			Assert.IsTrue(NumberUtils.IsNumber(10));
-			Assert.IsTrue(NumberUtils.IsNumber(10L));
-			Assert.IsTrue(NumberUtils.IsNumber((short) 10));
-			Assert.IsFalse(NumberUtils.IsNumber('e'));
-			Assert.IsFalse(NumberUtils.IsNumber(null));
-			Assert.IsTrue(NumberUtils.IsNumber(9.5D));
-			Assert.IsTrue(NumberUtils.IsNumber(9.5F));
-			Assert.IsFalse(NumberUtils.IsNumber(this));
-			Assert.IsFalse(NumberUtils.IsNumber(null));
-			Assert.IsFalse(NumberUtils.IsNumber(string.Empty));
+            Assert.IsTrue(NumberUtils.IsNumber(10));
+            Assert.IsTrue(NumberUtils.IsNumber(10L));
+            Assert.IsTrue(NumberUtils.IsNumber((short)10));
+            Assert.IsFalse(NumberUtils.IsNumber('e'));
+            Assert.IsFalse(NumberUtils.IsNumber(null));
+            Assert.IsTrue(NumberUtils.IsNumber(9.5D));
+            Assert.IsTrue(NumberUtils.IsNumber(9.5F));
+            Assert.IsFalse(NumberUtils.IsNumber(this));
+            Assert.IsFalse(NumberUtils.IsNumber(null));
+            Assert.IsFalse(NumberUtils.IsNumber(string.Empty));
 		}
 
+        [Test]
+        public void IsZero()
+        {
+            Assert.IsFalse(NumberUtils.IsZero((Int16)2));
+            Assert.IsTrue(NumberUtils.IsZero((Int16)0));
+
+            Assert.IsFalse(NumberUtils.IsZero((Int32)2));
+            Assert.IsTrue(NumberUtils.IsZero((Int32)0));
+
+            Assert.IsFalse(NumberUtils.IsZero((Int64)2));
+            Assert.IsTrue(NumberUtils.IsZero((Int64)0));
+
+            Assert.IsFalse(NumberUtils.IsZero((UInt16)2));
+            Assert.IsTrue(NumberUtils.IsZero((UInt16)0));
+
+            Assert.IsFalse(NumberUtils.IsZero((UInt32)2));
+            Assert.IsTrue(NumberUtils.IsZero((UInt32)0));
+
+            Assert.IsFalse(NumberUtils.IsZero((UInt64)2));
+            Assert.IsTrue(NumberUtils.IsZero((UInt64)0));
+
+            Assert.IsFalse(NumberUtils.IsZero((decimal)2));
+            Assert.IsTrue(NumberUtils.IsZero((decimal)0));
+
+            Assert.IsTrue(NumberUtils.IsZero((Byte?)0));
+            Assert.IsFalse(NumberUtils.IsZero((Byte)2));
+
+            Assert.IsTrue(NumberUtils.IsZero((SByte?)0));
+            Assert.IsFalse(NumberUtils.IsZero((SByte)2));
+        }
+
 		[Test]
 		[ExpectedException(typeof(ArgumentException))]
 		public void NegateNull()
@@ -90,7 +121,7 @@ namespace Spring.Util
 		[ExpectedException(typeof(ArgumentException))]
 		public void NegateString()
 		{
-			NumberUtils.Negate(null);
+			NumberUtils.Negate(string.Empty);
 		}
 
 		[Test]